Once they navigate away from the topic, there’s no obvious workaround for them to retrieve their own post.
I agree that it’s not critical, but doesn’t seem trivial either, imho? Being able to reverse a delete of a post is a (nice!) base feature of Discourse that is even mentioned on the tutorial. But of course is up to the Discourse team to prioritise their work — just wanted to report that the issue is still present and I don’t expect an immediate fix. Would contribute with a fix myself if I understood enough of the codebase, but I’m afraid I do not.